2010 Hurricane Season Outlook and Considerations

2010 Hurricane Season Outlook and Considerations

Jeff Garmon

Warning Coordination Meteorologist

David McShane

Meteorologist in Charge

NOAA – National Weather Service

Weather Forecast Office Mobile, AL

Jeff Garmon

Warning Coordination Meteorologist

David McShane

Meteorologist in Charge

NOAA – National Weather Service

Weather Forecast Office Mobile, AL

National Weather ServiceHurricane Forecasting Operations

National Weather ServiceHurricane Forecasting Operations

• National Hurricane Center (Miami)National Hurricane Center (Miami)

– Track and model forecast guidance

– Broad-scale track and intensity parameters

• NWS Forecast Office (Mobile)NWS Forecast Office (Mobile)

– Storm-scale impacts and timing

• Winds

• Surge

• Tornadoes

• Rainfall

• National Hurricane Center (Miami)National Hurricane Center (Miami)

– Track and model forecast guidance

– Broad-scale track and intensity parameters

• NWS Forecast Office (Mobile)NWS Forecast Office (Mobile)

– Storm-scale impacts and timing

• Winds

• Surge

• Tornadoes

• Rainfall

The Good track forecast improvements

The Good track forecast improvements

Changes to Tropical Cyclone Watch/Warning Lead Times in 2010

Changes to Tropical Cyclone Watch/Warning Lead Times in 2010

• Lead time virtually unchanged while skill in track forecasting has improved

• NHC in fact frequently does issue watches and warnings at longer lead time than Directive indicates

• Key evacuation decisions now need to be made before 24 h and in some cases before 48 h

• Some jurisdictions, businesses, and schools still tag closure decisions to warning or watch

• Lead time virtually unchanged while skill in track forecasting has improved

• NHC in fact frequently does issue watches and warnings at longer lead time than Directive indicates

• Key evacuation decisions now need to be made before 24 h and in some cases before 48 h

• Some jurisdictions, businesses, and schools still tag closure decisions to warning or watch

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

50,000,000

1900

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

Coastal County Population,

Texas to Maine

Coastal County Population,

Texas to Maine

53% of the U.S. population now lives 53% of the U.S. population now lives within 50 miles of the coast within 50 miles of the coast

YearYear

Pop

ula

tion

Pop

ula

tion

New for 2010New for 2010

• Tropical Storm / Hurricane Warnings will be issued for onset of Tropical Storm / Hurricane conditions 36 hours in advance.

• Tropical Storm / Hurricane Watches will be issued for onset of Tropical Storm / Hurricane conditions 48 hours in advance.

• Tropical Storm / Hurricane Warnings will be issued for onset of Tropical Storm / Hurricane conditions 36 hours in advance.

• Tropical Storm / Hurricane Watches will be issued for onset of Tropical Storm / Hurricane conditions 48 hours in advance.

The Bad Intensity no real gains

The Bad Intensity no real gains

The Ugly – Un-forecasted Rapid Intensity Changes

The Ugly – Un-forecasted Rapid Intensity Changes

Even some of our best models miss the mark substantiallyEven some of our best models miss the mark substantially

• 1932 – TS 180 miles south of GLS – Cat 4 at landfall less than 36h

• 1943 , Alicia – both formed south of NOLA landfall less than 72h

• Audrey June 1957 – Cat 4 less then 72h after forming

• Anita (5), Celia (4), Camille (5) and Opal (4) all less then 96h

• 1932 – TS 180 miles south of GLS – Cat 4 at landfall less than 36h

• 1943 , Alicia – both formed south of NOLA landfall less than 72h

• Audrey June 1957 – Cat 4 less then 72h after forming

• Anita (5), Celia (4), Camille (5) and Opal (4) all less then 96h

Gulf of Mexico Rapid Intensifiers

Gulf of Mexico Rapid Intensifiers

1935 Labor Day Hurricane Category 1 to Category 5 in just 36h

1935 Labor Day Hurricane Category 1 to Category 5 in just 36h

7 am Sept 1 7 am Sept 1 Cat 1Cat 1

OO

1 am Sept 2 1 am Sept 2 Cat 3Cat 3

O7 pm Sept 2 7 pm Sept 2 Cat 5Cat 5

Storm surge uncertaintyStorm surge uncertainty

• Extremely sensitive to errors in track, size, structure of wind field, angle of approach, and forward speed.

• Improvement in meteorological forecast over next decade will not negate the error function for surge forecast.

• Always expect enough track/intensity error to change the deterministic surge forecast...even 12 hours in advance.

• Extremely sensitive to errors in track, size, structure of wind field, angle of approach, and forward speed.

• Improvement in meteorological forecast over next decade will not negate the error function for surge forecast.

• Always expect enough track/intensity error to change the deterministic surge forecast...even 12 hours in advance.

Hurricane Advisory – Approximately 12 hr. before landfall

NHC TRACK ERROR 12 hr. OUT

133 mph, 933 mb.

Rmax=25 mi(forecast)

Surge Based on NHC -12 hr. Advisory

Actual Hurricane Track 30 mi. E of -12 hr. Advisory Forecast Track

TRACK FORECAST

ACTUAL TRACK

133 mph, 933 mb.

Rmax=40 mi

Surge Based on NHC Storm Best Track

SLOSH Storm Surge (MEOW Cat 3 High Tide)…

SLOSH Storm Surge (MEOW Cat 3 High Tide)…

LL

HH

LL

HH

5,000 ft/850 mb5,000 ft/850 mb

40,000 ft/200 mb40,000 ft/200 mb

Heat

Heat

He

at

He

at

Typical cruising altitude of commercial airplane

SurfaceSurface

Effect of Vertical Wind ShearEffect of Vertical Wind Shear

El Nino – La Nina effects the El Nino – La Nina effects the position of the Jetstreamposition of the Jetstream

El Nino – La Nina effects the El Nino – La Nina effects the position of the Jetstreamposition of the Jetstream

Stronger southern stream upper jet = more wind shear over GulfStronger southern stream upper jet = more wind shear over Gulf

What can we expect in 2010?What can we expect in 2010?What can we expect in 2010?What can we expect in 2010?

El Nino is gone. Weak La Nina possible by El Nino is gone. Weak La Nina possible by mid to late summer. mid to late summer.

• Decreased wind shear values will very likely Decreased wind shear values will very likely mean a marked increase in activity compared mean a marked increase in activity compared to last year. to last year.

• Significant wind shear due to a Significant wind shear due to a strengthening El Nino in 2009 resulted in a strengthening El Nino in 2009 resulted in a below average number of storms in the below average number of storms in the Atlantic Basin in 2009.Atlantic Basin in 2009.

El Nino is gone. Weak La Nina possible by El Nino is gone. Weak La Nina possible by mid to late summer. mid to late summer.

• Decreased wind shear values will very likely Decreased wind shear values will very likely mean a marked increase in activity compared mean a marked increase in activity compared to last year. to last year.

• Significant wind shear due to a Significant wind shear due to a strengthening El Nino in 2009 resulted in a strengthening El Nino in 2009 resulted in a below average number of storms in the below average number of storms in the Atlantic Basin in 2009.Atlantic Basin in 2009.

Model-Based El Niño/ La Niña (ENSO) Model-Based El Niño/ La Niña (ENSO) Forecasts for the Niño 3.4 regionForecasts for the Niño 3.4 region

Model-Based El Niño/ La Niña (ENSO) Model-Based El Niño/ La Niña (ENSO) Forecasts for the Niño 3.4 regionForecasts for the Niño 3.4 region

The ENSO forecast models are predicting either ENSO-Neutral or La The ENSO forecast models are predicting either ENSO-Neutral or La Niña conditions during the Atlantic hurricane season. The forecasts are Niña conditions during the Atlantic hurricane season. The forecasts are increasingly indicating La Niña during Aug-Oct (ASO) 2010 (Figure increasingly indicating La Niña during Aug-Oct (ASO) 2010 (Figure courtesy of the International Research Institute).courtesy of the International Research Institute).

El Niño

La Niña

ENSO-Neutral

Pacific Ocean Conditions are favorable Pacific Ocean Conditions are favorable for La Niña to Developfor La Niña to Develop

12

Weekly SST (oC)Centered on 12 May 2010

El Niño has dissipated. Negative SST anomalies are now present in the equatorial Pacific.

Subsurface Temperatures (oC)5-day Mean Centered 13 May 2010

Sub-surface temperatures are below average across the eastern half of equatorial Pacific.

Equatorial Upper Ocean (0-300m) Heat Content 180o-100oW

Since March 2010, the oceanic heat content has decreased markedly.

Expected Atlantic Basin Conditions During August-October 2010

Expected Atlantic Basin Conditions During August-October 2010

7

Much Warmer Atlantic SSTs

The predicted set of conditions forThe predicted set of conditions forAugust-October 2010 mainly August-October 2010 mainly reflectsreflects the expected the expected continuation of the tropical multi-decadal signal, above-average Atlantic Ocean continuation of the tropical multi-decadal signal, above-average Atlantic Ocean temperatures, and a possible La Niña-related reduction in vertical wind shear. temperatures, and a possible La Niña-related reduction in vertical wind shear.

Vertical Wind Shear (m s-1)

850-hPa Winds (m s-1)

Tropical low-level westerly wind anomalies across eastern Pacific and Atlantic (Blue circle).

Reduced vertical wind shear across heart of the MDR (Blue shading in green box).

200-hPa Winds (m s-1)

Tropical upper-level easterly wind anomalies across eastern Pacific and Atlantic (Blue circle).

Anticyclonic anomalies across tropical Atlantic in both hemispheres (Blue circle).

200-hPa Streamfunction

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Recent Circulation Anomalies (Last 30 days)Recent Circulation Anomalies (Last 30 days)Typically Associated With Active Atlantic Phase Typically Associated With Active Atlantic Phase

of Tropical Multi-decadal Signalof Tropical Multi-decadal Signal

SST departures in the MDR increased sharply SST departures in the MDR increased sharply during February-April 2010 (Top), and reached during February-April 2010 (Top), and reached record levels in March and April. These record levels in March and April. These departures are much larger elsewhere in the departures are much larger elsewhere in the global Tropics (Bottom), indicating a local global Tropics (Bottom), indicating a local warming rather than global warming.warming rather than global warming.

Warmer SSTs in the Tropical AtlanticWarmer SSTs in the Tropical Atlantic

Latest Weekly SST Departures (Latest Weekly SST Departures (ooC)C) Monthly SST Departures (Monthly SST Departures (ooC)C)

The Main Development Region (MDR) for Atlantic The Main Development Region (MDR) for Atlantic hurricanes (Green Box) is currently experiencing hurricanes (Green Box) is currently experiencing record warm SSTs, with departures exceeding record warm SSTs, with departures exceeding +1.5+1.5ooC nearly everywhere east of the Caribbean C nearly everywhere east of the Caribbean Islands.Islands.

The 2010 Atlantic Outlook in a Historical Perspective

The 2010 Atlantic Outlook in a Historical Perspective

NOAA’s 2010 Atlantic hurricane season outlook indicates NOAA’s 2010 Atlantic hurricane season outlook indicates a 70% a 70% probability of an ACE range of 155%-270% of the medianprobability of an ACE range of 155%-270% of the median. .

An ACE value above 175% of median reflects an extremely active (also An ACE value above 175% of median reflects an extremely active (also called hyperactive) season.called hyperactive) season.

Based on this forecast, I will:Based on this forecast, I will:

• A) Plan for more impacts than last year

• B) Cry “Holy &^%$” and move to Canada

• C) Do the same as every year

• A) Plan for more impacts than last year

• B) Cry “Holy &^%$” and move to Canada

• C) Do the same as every year

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Seasonal Forecast 2010…it only takes one…

Seasonal Forecast 2010…it only takes one…

33

Andrew

Track Map

Tropical cyclones are born, live, and die in a variety of ways

Tropical cyclones are born, live, and die in a variety of ways

HH

Oil Spill and Gulf StormsOil Spill and Gulf Storms

• Direct hit of major storm – big surge more damaging than oil (life threatening and mix of toxic material from damage caused by surge)

• Weak storm or large storm passing well to south raises water levels 2 to 5 feet bringing oil to places previously untouched.

• Direct hit of major storm – big surge more damaging than oil (life threatening and mix of toxic material from damage caused by surge)

• Weak storm or large storm passing well to south raises water levels 2 to 5 feet bringing oil to places previously untouched.

Contact InformationContact InformationContact InformationContact Information

Jeff.Garmon@noaa.govJeff.Garmon@noaa.gov

251-633-6443 x223251-633-6443 x223

David.McShane@noaa.govDavid.McShane@noaa.gov

251-633-6443 x222251-633-6443 x222

Jeff.Garmon@noaa.govJeff.Garmon@noaa.gov

251-633-6443 x223251-633-6443 x223

David.McShane@noaa.govDavid.McShane@noaa.gov

251-633-6443 x222251-633-6443 x222